<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8"/>
        <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
        <meta http-equiv="X-UA-Compatible" content="ie=edge"/>
        <title>Document</title>
        <script src = 'jquery-1.10.1.min.js'></script>
        <script>
            $(function(){
                /* 
                    innerHTML
                    value
                 */

               /*   alert($("#div1").html());

                 $("#div1").html("<h2>我是新赋值的内容</h2>") */


                 alert($("input").val());
                 $("input").val("world hello");
            })
        </script>
    </head>
    <body>
        <div id = 'div1'>
            <em>em</em>
            div文本
        </div>
        <input type="text" value = 'helloworld'/>
    </body>
</html>